Group B streptococcus (GBS) is one of the severe pathogenic bacteria during the perinatal period, both on pregnant women and newborns. GBS infection may lead to pneumonia, septicemia, meningitis or other severe disease, even death in neonates. Although only 1%-2% infections will develop into GBS disease among the neonates, the etiological mechanism of which is worth researching. This review summarizes the possible factors related to GBS infection or occurrence of the disease, including the risk in gestation period (for example, colonization of GBS on vagina of pregnant women, preterm birth or premature rupture of fetal membranes and so on), related pathogens (bacteria strains, loads or virulence), immune level (inflammatory factor or neutralizing anticytokine auto-Abs), gene defect or primary immunodeficiencies of the hosts.
Female ; Humans ; Infant, Newborn ; Infectious Disease Transmission, Vertical ; Pregnancy ; Pregnancy Complications, Infectious/urine* ; Premature Birth ; Streptococcal Infections/urine* ; Streptococcus agalactiae/isolation & purification* ; Vagina/microbiology*

BACKGROUND: Group B streptococcus (GBS) infection is a leading cause of neonatal morbidity and mortality worldwide. Here, we present the analytical and diagnostic usefulness of a new real-time PCR-based assay (Xpert GBS; Cepheid, USA) for rapid and accurate prenatal GBS screening. METHODS: We enrolled 175 pregnant women who were between 35 and 39 weeks of gestation. The analytical performance of the Xpert GBS assay was first tested using a reference GBS strain. Next, to test diagnostic performance, rectovaginal swabs were obtained from pregnant women who visited the hospital for regular antenatal screening after 34 weeks of gestation. The results of the Xpert GBS assay were compared to those of standard culture for the detection of prenatal GBS colonization. RESULTS: When any positive result from Xpert GBS or culture was considered a true positive, the sensitivity of the Xpert GBS assay and culture were 91% (20/22; 95% CI [confidence interval], 72-98) and 68% (15/22; 95% CI, 47-84), respectively. The specificity of both methods was 100% (153/153; 95% CI, 97-100). The sensitivity and specificity of the Xpert GBS assay, using the culture results as a reference, were 86.7% and 95.6%, respectively. In the Xpert GBS assay, the median threshold cycle of vaginally colonized samples was significantly lower than rectally colonized samples (P<0.01). CONCLUSIONS: The Xpert GBS assay is an accurate, rapid, easy-to-use test for the detection of maternal GBS colonization in prenatal screening that might be especially useful in clinical settings where standard culture is not feasible.
DNA, Bacterial/*analysis ; Female ; Gestational Age ; Humans ; Pregnancy ; Pregnancy Complications, Infectious/*diagnosis/microbiology ; Prenatal Diagnosis ; Reagent Kits, Diagnostic ; Real-Time Polymerase Chain Reaction ; Rectum/microbiology ; Sensitivity and Specificity ; Streptococcal Infections/*diagnosis/microbiology ; Streptococcus agalactiae/*genetics/isolation & purification ; Vagina/microbiology

OBJECTIVETo investigate the impact of intrauterine infection induced by LPS injection on long-term brain development of premature rats.

METHODSEighteen day-gestation pregnant rats were randomly assigned to a control group receiving an intraperitoneal injection of normal saline, and two infection groups that were intraperitoneally injected with 0.3 mg/kg or 0.6 mg/kg LPS. Twenty-four hours after injection, 7 pregnant rats of each group were sacrificed. The pathological changes of the placenta after hematoxylin and eosin staining were observed under a light microscope. The neural cell apoptosis of fetal brains was examined by the TUNEL assay. The remained pregnant rats were induced to labour before 21 gestation days. The long-term brain development of premature rats was tested with the Y type electric maze on postnatal day 42.

RESULTSObvious pathological changes were observed in the placenta in the infection groups. The apoptotic neural cells in the fetal brain increased in the infection groups compared with that in the control group (32.41+/-5.36 in the 0.3 mg/kg infection group and 66.41+/-7.61 in the 0.6 mg/kg infection group vs 8.00+/-0.36 in the control group; P<0.01). The number of trials to criterion in the Y type maze test in the infection groups was much more than that in the control group [117.8+/-8.7 (0.3 mg/kg infection group) and 194.4+/-13.7 (0.6 mg/kg infection group) vs 56.8+/-3.7 (control group); P<0.01]. The number of correct reactions in memory retaining in the infection groups was lower than that in the control group (0.62+/-0.09 in the 0.3 mg/kg infection group and 0.37+/-0.09 in the 0.6 mg/kg infection group vs 0.92+/-0.06 in the control group; P<0.05).

CONCLUSIONSIntrauterine infection can cause fetal rats' neural cell apoptosis and affect adversely long-term brain development of neonatal rats.

Animals ; Apoptosis ; Bacterial Infections ; physiopathology ; Blood-Brain Barrier ; Brain ; growth & development ; pathology ; Female ; Maze Learning ; Neurons ; pathology ; Pregnancy ; Pregnancy Complications, Infectious ; physiopathology ; Rats ; Rats, Wistar ; Uterus ; microbiology

OBJECTIVETo establish a methed of cleavage fragment length polymorphism (CFLP) analysis with a primer labeled at the 5'-end with digoxigenin for genotyping of Chlamydia trachomatis (Ct). The methods for detection of Ct by major outer membrane protein (MOMP) gene (ompl) with nested polymerase chain reaction (ompl-nPCR) were studied. The incidence of Ct infection in pregnant women, the common genotypes and vertical transmission rate of Ct in Chongqing area during the past one year was also investigated.

METHODSThe samples were taken from cervical scrapes of parturient women and nasopharygeal swabs of their neonates from April 2003 to Feb. 2004 in Chongqing Women and Children's Health Care Institute. Totally 300 pairs (605 specimens) were detected by using ompl-nPCR, ompl-PCR (inside pair of primers was used directly) and plasmid-PCR. The results were judged by the modified gold standard (MGS). The ompl-nPCR amplified DNA was purified by recovery of DNA from agarose gel electroelution into dialysis bags. The DNA amplified from ompl-nPCR was sequenced by ABI PRISM 377 DNA sequencer. CFLP assay with a primer labeled at the 5'-end with digoxigenin was created for genotyping of Ct, and was primarily applied.

RESULTSThe minimum detectable levels of ompl-nPCR and ompl-PCR corresponded to 2.5 elementary body (EB) and 25 EB, respectively. The sensitivity of ompl-nPCR was 10 times that of ompl-PCR. The positive rate of Ct in the samples from the pregnant women was 11% (33/300). The vertical transmission rate of Ct from mothers to their infants was 24.2% (8/33). The rate of Ct isolated from nasopharyngeal swabs 5 - 10 days after birth was 38.9% (7/18), which was significantly greater than that [3.0% (1/33)] detected within 24 hours after birth (chi(c)(2) = 8.79, P < 0.01). Of the 33 Ct-positive samples from pregnant women, 9 had vaginal delivery and 24 had caesarean section. The vertical transmission rates in vaginal delivery group and caesarean section group were 66.7% (6/9) and 8.3% (2/24), respectively (chi(c)(2) = 9.16, P < 0.01). Incidence of premature rupture of membrane in Ct-positive group was 30.3% (10/33), which was greater than that of Ct-negative groups (13.5%, 36/267, chi(2) = 6.40, P < 0.05). Four different patterns were observed in the 16 Ct-positive samples from 8 pregnant women and 8 matched maternal-infants by using CFLP, which were confirmed by DNA sequencing later. They were type E (3 pairs), type F (2 pairs), type H (2 pairs) and type D (1 pair). Each pair of matched maternal-infantile samples presented identical CFLP pattern.

CONCLUSIONSThis study revealed the infection rate of Ct in pregnant women, vertical transmission rate of Ct and the common genotypes of Ct in Chongqing Women and Children's Health Care Institute. The CFLP assay by using a primer labeled at the 5'-end with digoxigenin was first used for genotyping of Ct. The assay showed a good sensitivity and reproducibility, no radioactive contamination, and is simple. Therefore the assay is a potential new method for Ct genotyping.

Cervix Uteri ; microbiology ; Chlamydia Infections ; diagnosis ; Chlamydia trachomatis ; genetics ; DNA Primers ; Female ; Genes, Bacterial ; genetics ; Genotype ; Humans ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Pregnancy ; Pregnancy Complications, Infectious ; diagnosis

Helicobacter pylori (H. pylori) infection is acquired mainly in early childhood but the precise transmission routes are unclear. This study examined the maternal H. pylori infection status in order to determine the potential of perinatal transmission. These issues were investigated using an experimental murine model, the Mongolian gerbil, which has been reported to be the most suitable laboratory animal model for studying H. pylori. Pregnant Mongolian gerbils, infected experimentally with H. pylori, were divided into two groups. The stomachs of the mother and litters were isolated and assessed for the transmission of H. pylori at the prenatal period (2 weeks after pregnancy) and at the parturition day. The bacterial culture, polymerase chain reaction (PCR) and rapid urease test were used to examine the presence of the transmitted H. pylori. There was no H. pylori observed in any of the fetuses during pregnancy and in the litters at parturition. This suggests that vertical infection during the prenatal period or delivery procedure is unlikely to be route of mother-tochild transmission of a H. pylori infection.
Animals ; Animals, Newborn ; Disease Models, Animal ; *Disease Transmission, Vertical ; Female ; Gerbillinae ; Helicobacter Infections/microbiology/*transmission ; Helicobacter pylori/*growth&development ; Male ; Polymerase Chain Reaction ; Pregnancy ; Pregnancy Complications, Infectious/*microbiology ; Specific Pathogen-Free Organisms ; Stomach Diseases/*microbiology

BACKGROUND: To investigate the risk factors for vaginal infections and antimicrobial susceptibilities of vaginal microorganisms among women who experienced preterm birth (PTB), we compared the prevalence of vaginal microorganisms between women who experienced preterm labor (PTL) without preterm delivery and spontaneous PTB. METHODS: Vaginal swab specimens from 126 pregnant women who experienced PTL were tested for group B streptococcus (GBS), Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum, Chlamydia trachomatis, Trichomonas vaginalis, Neisseria gonorrhoeae, Treponema pallidum, herpes simplex virus (HSV) I and II, and bacterial vaginosis. A control group of 91 pregnant women was tested for GBS. Antimicrobial susceptibility tests were performed for GBS, M. hominis, and U. urealyticum. RESULTS: The overall detection rates for each microorganism were: U. urealyticum, 62.7%; M. hominis, 12.7%; GBS, 7.9%; C. trachomatis, 2.4%; and HSV type II, 0.8%. The colonization rate of GBS in control group was 17.6%. The prevalence of GBS, M. hominis, and U. urealyticum in PTL without preterm delivery and spontaneous PTB were 3.8% and 8.7% (relative risk [RR], 2.26), 3.8% and 17.3% (RR, 4.52), and 53.8% and 60.9% (RR, 1.13), respectively, showing no significant difference between the 2 groups. The detection rate of M. hominis by PCR was higher than that by culture method (11.1% vs. 4.0%, P=0.010). The detection rates of U. urealyticum by PCR and culture method were 16.7% and 57.1%, respectively. CONCLUSIONS: There was no significant difference in the prevalence of GBS, M. hominis, and U. urealyticum between the spontaneous PTB and PTL without preterm delivery groups.
Female ; Humans ; Microbial Sensitivity Tests ; Mycoplasma Infections/complications/microbiology ; Mycoplasma hominis/isolation & purification ; Obstetric Labor, Premature/*epidemiology/etiology ; Pregnancy ; Pregnancy Complications, Infectious/epidemiology/microbiology ; Premature Birth/*epidemiology/etiology ; Prevalence ; Risk Factors ; Streptococcal Infections/complications/microbiology ; Streptococcus agalactiae/isolation & purification ; Ureaplasma Infections/complications/microbiology ; Ureaplasma urealyticum/isolation & purification ; Vagina/*microbiology

OBJECTIVETo examine the expression of tumor necrosis factor in placenta of pregnant rats with chronic periodontitis.

METHODSTwenty Wistar female rats were randomly divided into two groups, control (n = 8) and experimental group (n = 12). The periodontitis model was established in the experimental group. The females and males in the two groups got together four weeks later. Nineteen days after pregnancy all rats were executed and placenta collected. The delivery time and neonatal birth weight were recorded and the pathological changes of periodontal tissue observed. Tumor necrosis factor (TNF) expression was examined in placenta by real-time quantitative polymerase chain reaction analysis.

RESULTSThe animal model of chronic periodontitis was successfully established. Experimental group delivered 30 offspring and the control group 56 offspring. The average number of pups born alive per litter in experimental group (4.1 ± 2.2) was significantly lower than that in control group (9.2 ± 2.2), P < 0.05. The birth weight of pups in experimental group [(5.01 ± 0.43) g] was significantly lower than that in the control group [(5.79 ± 0.53) g], P < 0.05. The relative quantitative expression of TNF was (1.807 ± 0.265) in experimental group the and (1.003 ± 0.021) in the control group (P = 0.001).

CONCLUSIONSChronic periodontitis may be related to preterm low birth weight.

Aggregatibacter actinomycetemcomitans ; Animals ; Animals, Newborn ; Birth Weight ; Chronic Periodontitis ; metabolism ; microbiology ; Disease Models, Animal ; Female ; Fusobacterium nucleatum ; Placenta ; metabolism ; Porphyromonas gingivalis ; Pregnancy ; Pregnancy Complications, Infectious ; metabolism ; microbiology ; Prevotella intermedia ; Random Allocation ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the indigenous lactobacilli from the vagina of pregnant women and to screen the isolates with antagonistic potential against pathogenic microorganisms.

METHODSThe strains were isolated from pregnant women's vagina and identified using the API50CH system. The ability of the isolates to produce hydrogen peroxide was analyzed semi-quantitatively using the TMB-HRP-MRS agar. The antagonistic effects of the isolates on pathogenic microorganisms were determined with a double layer agar plate.

RESULTSOne hundred and three lactobacilli strains were isolated from 60 samples of vaginal secretion from healthy pregnant women. Among them, 78 strains could produce hydrogen peroxide, in which 68%, 80%, 80%, and 88% had antagonistic effects against Candida albicans CMCC98001, Staphylococcus aureus CMCC26003, Escherichia coli CMCC44113, and Pseudomonas aeruginosa CMCC10110, respectively.

CONCLUSIONThe recovery of hydrogen peroxide-producing lactobacilli decreases with the increasing pregnant age and time. The most commonly isolated species from vagina of Chinese pregnant women are Lactobacillus acidophilus and Lactobacillus crispatus. Most of L. acidophilus and L. crispatus produce a high H2O2 level.

Adult ; Asian Continental Ancestry Group ; Bacterial Physiological Phenomena ; Candida albicans ; physiology ; Female ; Humans ; Hydrogen Peroxide ; Lactobacillus ; isolation & purification ; metabolism ; Pregnancy ; Pregnancy Complications, Infectious ; epidemiology ; Vagina ; microbiology ; Vaginosis, Bacterial ; microbiology

Adult ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Genital Diseases, Female ; drug therapy ; microbiology ; Humans ; Phytotherapy ; Pregnancy ; Pregnancy Complications, Infectious ; drug therapy ; Sexually Transmitted Diseases, Bacterial ; drug therapy ; Ureaplasma Infections ; drug therapy ; Ureaplasma urealyticum

PURPOSE: There is a concern on which antimicrobials are appropriate as empirical agents for community-onset acute pyelonephritis (APN) in regions where the fluoroquinolone resistance rate is high, such as in Korea. MATERIALS AND METHODS: Three hundred and two strains of E. coli in 2001-2002 and 349 strains in 2008-2009 were isolated from the urine cultures of female adult APN patients, and the antimicrobial susceptibility was compared according to each study period. All the patients were classified as uncomplicated or complicated APN, and a subgroup analysis was done thereafter. RESULTS: The E. coli strains isolated in 2008-2009 showed improved susceptibility to trimethoprim-sulfamethoxazole compared to those isolated in 2001-2002. However, the third generation cephalosporin and gentamicin susceptibility was worsened. Of the 232 isolates from the uncomplicated APN patients, there was no difference between the two different time periods. On the other hand, of the 419 isolates from the complicated APN patients, the susceptibility to third generation cephalosporin, gentamicin and ciprofloxacin was significantly worsened. CONCLUSION: The antimicrobial susceptibility of E. coli changed over the study period, however, this change occurred mainly in the complicated APN patients. In Korea, ciprofloxacin is still useful as an empirical agent for uncomplicated APN patients, but this is not the case for patients with complicated APN because of high resistance rate to ciprofloxacin in these patients. For the complicated APN patients, the rate of resistance to ciprofloxacin is already more than 30%.
Acute Disease ; Adult ; Aged ; Anti-Bacterial Agents/*therapeutic use ; Ciprofloxacin/*therapeutic use ; Community-Acquired Infections/*drug therapy/microbiology ; *Drug Resistance, Bacterial ; Escherichia coli Infections/*drug therapy/microbiology ; Female ; Humans ; Middle Aged ; Pregnancy ; Pregnancy Complications, Infectious/drug therapy/microbiology ; Pyelonephritis/*drug therapy/microbiology